The Gyde Heated Puffer Jacket, powered by Gerbing Technology, is the most technologically advanced 800-fill jacket on the market. Powered by Gerbing Coreheat 7 technology, the Gyde Heated Puffer Jacket is a standalone battery powered heating system. This system maxes out at 135F degrees, and is powered by a 7 volt 2.2Ah lithium-ion battery. This is the premier jacket for anyone struggling to deal with the extreme cold temperatures. The combination of battery powered heat and naturally produced body heat being stored by the 800-fill down makes for unbeatable warmth.